With continuous development of flexible display products, a Roll-to-Roll process will be gradually used as main manufacturing process in future display production field, replacing the current method of fabricating display product one by one, by virtue of its low cost and characteristics of high efficiency production.
FIG. 1 is a schematic diagram of conventional roll-to-roll etching apparatus, comprising an etching tank 12 accommodating an etching liquid 11; winding rollers located above the etching tank 12, which includes a main roller 13 and a driven roller 14; and a positioning roller 15 located in the etching liquid 11, wherein a flexible substrate 16 is passed around the driven roller 14, the positioning roller 15 and the main roller 13 along its movement direction.
As the apparatus shown in FIG. 1 operates, a flexible substrate 16 is performed through a roll-to-roll etching process. The main roller 13 is rotated and the flexible substrate 16 is driven from the driven roller 14 toward the main roller 13 and passes around the positioning roller 15 in the etching liquid 11. During being immersed in the etching liquid, part of the flexible substrate 16 is etched.
However, with regard to the conventional roll-to-roll etching process, since the diameters of the main roller 13 and the driven roller 14 are both changed with the number of the wrapped flexible substrate layers, the line velocities of the moving flexible substrate on the main roller 13 in uniform rotation and the driven roller 14 will constantly change. As a result, etching time of the immersed flexible substrate 16 is changed with the diameters of the main roller 13 and the driven roller 14 being changed, which will leads to uneven size of devices formed on the flexible substrate and influences qualities of flexible display products.